Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only supply readOnlyHint, so the description carries the rest and does well: it discloses auth requirement ('Needs the API V3 token') and the cursor pagination mechanics. It omits return shape and rate limit context, so short of a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences plus an endpoint reference; front-loaded with purpose, then filters, then auth and pagination. No filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

A read-only list tool with no output schema and fully documented params; the description covers filters, auth, and pagination. Minor omission: no note on default page size or result ordering, but the schema covers limit.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% so the baseline is 3, but the description adds value by pre-classifying the filters (partial/case-insensitive for name, exact for code and CIF) and explaining the cursor pagination protocol that the schema only hints at.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Specific verb (list) + resource (clients) with the exact filter semantics spelled out (name partial/case-insensitive, code exact, CIF exact). Distinguishes itself from the sibling smartbill_get_client by being the bulk/search variant.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives clear context for when to use it (bulk list with optional filters) and describes the pagination contract ('pass next_args as next call's arguments'). It does not explicitly name smartbill_get_client as the single-client alternative, so not a full 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.